Stiffened container



Oct. 18, G. FEDER STIFFENED CONTAINER 2 Sheets-Sheet 1 Filed Aug. 6,1965 t wwww mp Q amt W A www Gad/ea Fem/c Z MJMWJ Oct. 18, 1966 G. FEDERSTIFFENED CONTAINER Filed Aug. 6, 1963 2 Sheets-Sheet 2 INVENTOR.

GEORG FED E'R Kfi KM United States Patent 3,279,500 STIFFENED CONTAINERGeorg Feder, Linz, Austria, assignor to Vereinigte OsterreichischeEisenund Stahlwerke Aktieugesellschaft,

Linz, Austria Filed Aug. 6, 1963, Ser. No. 300,233 Claims priority,application Austria, Oct. 10, 1962, A 7,996/ 62 5 Claims. '(Cl. 138-110)The wall thickness of underground pipes and containers of metals or ofmaterials having elastic properties similar to those of metal isfrequently determined in dependence on the stresses which are due to theexternal loads applied by the overlying soil because this load may causehigher stresses than the internal pressure. For the sake of economy,however, it is desired to give the pipe only the wall thickness requiredinview of the internal pressure and to provide additional stilfeningmeans to resist the load applied by the soil pressure. It is alreadyknown to provide rings or annular ribs as stifiening means on theoutside of the tube or to use concrete coverings for this purpose.Difficulties arise, however, adjacent to the stiffening rings withrespect to the protection against corrosion, and concrete coverings areexpensive and sensitive to a subsidence of the soil. Both kinds ofstiffening means have also the common disadvantage that they are notcapable or are capable only to a slight degree of producing a soilreaction pressure on the sides of the pipe. In the absence of a solidreaction pressure on the sides of the pipe, there will be no abutmentforce so that the upper half of the pipe acts as a beam rather than asan arch and the stresses will be multiplied.

It is an object of the invention to avoid all these disadvantages andprovide reinforced pipe assembly which is capable of taking up the loadfrom the overlying soil without involving difliculties regardingprotection from corrosion and without adversely effecting the reactionpressure of the soil on the sides of the pipe.

The pipe according to the invention consisting of metal or similarlyelastic material and intended for being loaded by soil pressure isessentially characterized in that the pipe is provided only at theupwardly facing portion of its peripheral wall with external stilfeningmeans, which are at least approximately crescent-shaped incross-section. Because such stiffening means have only smooth surfaces,they will not interfere with the protection against corrosion. On thecontrary, a particularly good protection is provided for the upperportion of the pipe, which is particularly liable to be corroded byfrost, roots, humus and the like. Besides, the external stiffening meansprovide a heat insulation around the upper portion of the pipe so thatthe danger of a formation of ice on the inside surface of the pipe iseliminated or at least substantially reduced. Loads from above which arecaused by vehicles moving over the pipe are distributed over arelatively large pipe section. Finally, the design according to theinvention has the important advantage that the pipe is stiffened at itsapex, which is most susceptible to denting, whereas the elasticproperties of the pipe are not appreciably reduced so that the action ofthe reaction pressure of the soil is preserved.

The external stiffening means may comprise a shell member joined to thepipe to define a cavity with it and consisting of the same material asthe pipe or of a material which is similar in elastic properties to thematerial of the pipe. The cavity may contain a filler, such as concreteor insulating material, or may be divided by partitions. Alternatively,the external stiifening means may consist of a solid body, for instance,of concrete.

The invention is not restricted to pipes but may also applied tocylindrical containers. The structures need not consist of undergroundpipes or containers because the invention includes also otherapplications with the same or similar loading conditions.

FIG. 1 shows embodiment of the invention in a transverse sectional view;

FIG. -2 illustrates a modification of the pipe arrangement of FIG. 1 ina corresponding view; and

FIG. 3 shows another m-odfified embodiment in a perspeotive view withportions of an outer shell removed to reveal internal structure.

FIG. 1 shows' an imperforate underground pipe 1, which has welded to theupper portion of its periphery the two axial edges of a shell 2. Thepipe 1 and shell 2 are of the same material. The pipe 1 and the shell 2define therebetween a cavity 3. In the otherwise identical pipearrangement of FIG. 2, the cavity is occupied by a filler 31 ofconcrete. The modified arrangement shown in FIG. 3 includes peripherallyextending, stifiening 4 which axially divide the cavity 3. The shellmember 2 extends substantially throughout the length of the pipe in allillustrated embodiments and is of uniform cross section over its length.

What I claim is:

1. A reinforced pipe assembly comprising, in combination:

(a) an elongated, substantially cylindrical pipe member of resilientmaterial having an axis and an imperforate wall about said axis, aportion of said wall facing in a predetermined direction transverse ofsaid axis; and- (b) stiffening means axially coextensive with said pipemember,

(1) said stiffening means having two axial edge portions fixedlyfastened to said wall portion, and

(2) being of substantially sickle-shaped substantially uniform crosssection transversely of said axis.

2. An assembly as set forth in claim 1, wherein said stiffening meansinclude a shell member constituted by said edge portions and anintermediate portion of arcuate cross section, said intenmediate portiondefining a cavity with said wall portion.

3. An assembly as set forth in'claim 2, wherein said stiffening meansfurther include a solid filler substantially filling said cavity.

4. An assembly as set forth in claim 3, wherein said filler is concrete.

5. An assembly as set forth in claim 2, wherein said stiffening meansfurther include a partition dividing said cavity.

References Cited by the Examiner UNITED STATES PATENTS 953,080 3/1910Wiggins 61-13 1,317,495 9/1919 Hessel 138-105 1,374,416 4/1921 Wilde61-13 2,057,176 10/ 1936 Willenberg 138-105 2,608,828 9/ 1952 Dimick61-11 FOREIGN PATENTS 104,986 8/1938 Australia.

LAVERNE D. GEIGER, Primary Examiner.

L'EWIS J. LENNY, T. MOORHEAD,

Assistant Examiners.

1. A REINFORCED PIPE ASSEMBLY COMPRISING, IN COMBINATION: (A) ANELONGATED, SUBSTANTIALLY CYLINDRICAL PIPE MEMBER OF RESILIENT MATERIALHAVING AN AXIS AND AN IMPERFORATE WALL ABOUT SAID AXIS, A PORTION OFSAID WALL FACING IN A PREDETERMINED DIRECTION TRANSVERSE OF SAID AXIS;AND (B) STIFFENING MEANS AXIALLY COEXTENSIVE WITH SAID PIPE MEMBER, (1)SAID STIFFENING MEANS HAVING TWO AXIAL EDGE PORTIONS FIXEDLY FASTENED TOSAID WALL PORTION, AND (2) BEING OF SUBSTANTIALL SICKLE-SHAPEDSUBSTANTIALLY UNIFORM CROSS SECTION TRANSVERSELY OF SAID AXIS.